There are many types of topical antiperspirant and deodorant products that are commercially available or otherwise known in the antiperspirant and deodorant art. Most of these products are formulated as aerosol or pump sprays, roll-on liquids, creams, emulsions, gels, gel-solids, or other solid or semi-solid stick formulations, and comprise a deodorant (e.g., triclosan) and/or astringent material (e.g. zirconium and/or aluminum salts) incorporated into a suitable carrier. These products are designed to provide effective perspiration and/or odor control while also being cosmetically acceptable during and after application onto the axillary area or other areas of the skin.
Within this product group, antiperspirant and deodorant products containing volatile silicone fluids have become especially popular among consumers. These products can be aqueous or anhydrous and can contain up to 80% by weight of a volatile silicone fluid such as cyclopentasiloxane. The volatile silicone provides the composition with dry skin feel during application, and because of its volatility, it evaporates quickly after application leaving the applied surface feeling smooth and dry with no residual white marks. Volatile silicones are expensive, however, and add substantially to the cost of the finished antiperspirant and deodorant products.
To control the relatively high formulation cost associated with the use of volatile silicone fluids, volatile, nonpolar hydrocarbon liquids have been used in place of some or all of the volatile silicones. Volatile nonpolar hydrocarbon liquids are typically less expensive than the volatile silicones, and like the volatile silicones, also help provide the composition with dry feel during and after application to the skin. Examples of compositions containing volatile, nonpolar hydrocarbon liquids are described in U.S. Pat. No. 4,724,139, issued Feb. 9, 1988 to Palinczar and U.S. Pat. No. 4,265,878, issued May 5, 1981 to Keil.
It has now been found, however, that antiperspirant and deodorant compositions containing volatile, nonpolar hydrocarbon liquids can be very irritating to the skin even when used at relatively low concentrations. It is believed that this irritation problem has not previously been disclosed in the literature as being associated with the use of these materials in deodorant and antiperspirant products. For example, U.S. Pat. No. 4,724,139 (Palinczar) teaches that volatile silicones can be replaced with volatile, nonpolar hydrocarbon liquids in antiperspirant sticks since the two materials have similar characteristics, including good cosmetics, high volatility, and low skin irritation. It has now been found, however, that these volatile, nonpolar hydrocarbon liquids when placed in either an antiperspirant or deodorant composition can cause significant skin irritation upon and after topical application even when the concentration of such liquids in the finished product is relatively low.
It has also now been found that antiperspirant and deodorant compositions containing a volatile, nonpolar hydrocarbon liquid can be formulated so as to minimize or eliminate the skin irritation caused by the volatile, nonpolar hydrocarbon liquid. It has been found that this skin irritation can be can be minimized or eliminated by the concurrent use of select solvents that act as skin irritation-mitigating materials (mitigating materials), provided that the weight ratio of the volatile, nonpolar hydrocarbon liquid to the mitigating material is from about 5:1 to about 1:50. The select solvents must have a vapor pressure equal to or less than that of the volatile, nonpolar hydrocarbon liquid. Highly preferred skin irritation-mitigating materials are nonvolatile silicone fluids.
It is therefore an object of the present invention to provide an antiperspirant or deodorant composition which contains a volatile, nonpolar hydrocarbon liquid, and which causes little or no skin irritation when applied topically to the axilla or other area of the skin. It is a further object of the present invention to provide such a composition which also contains a skin irritation-mitigating material, preferably a nonvolatile silicone fluid, to help minimize or eliminate the development of skin irritation after topical application.